Well if you are asking this because you think too much time has passed without his shed starting to come off, then not to worry, sometimes it takes quite a while for the skin underneath to be ready for the shed to come off. Don't ever, ever, ever try to help him shed or try to start the shed peeling off, as you'll hurt him badly and cause a bad infection. That's one of the main causes of Tail Roth, ripped-off toes, and horrible, deep wounds. You just have to let him do his thing. I've not ever seen a Dragon who started a shed and got "stuck" in the shed...They can sometimes have some "Retained Shed", but that typically happens in small patches after the shed is over, and you can help that off by giving them a warm
bath and putting some Coconut Oil on the patches of Retained Shed.
But as far as a Full-Body Shed or even an entire full-area shed, meaning an entire leg, tail, their head or back, etc., they will not get "stuck" inside it, it's simply that it's not ready to go yet.